Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Undersea forces from hurricanes may threaten Gulf pipelines

27.05.2010
Hurricanes could snap offshore oil pipelines in the Gulf of Mexico and other hurricane-prone areas, since the storms whip up strong underwater currents, a new study suggests.
These pipelines could crack or rupture unless they are buried or their supporting foundations are built to withstand these hurricane-induced currents. "Major oil leaks from damaged pipelines could have irreversible impacts on the ocean environment," the researchers warn in their study, to be published on 10 June in Geophysical Research Letters, a journal of the American Geophysical Union (AGU).

With the official start of hurricane season approaching on June 1, news reports about the Deep Horizon oil spill that began fouling the Gulf last month have raised questions about how a hurricane might complicate the unfolding disaster.

A hurricane might also create its own spills, the new research indicates. The storms' powerful winds can raise waves 20 meters (66 feet) or more above the ocean surface. But their effects underwater are little known, although signs of seafloor damage have showed up after some hurricanes.

Based on unique measurements taken directly under a powerful hurricane, the new study's calculations are the first to show that hurricanes propel underwater currents with enough oomph to dig up the seabed, potentially creating underwater mudslides and damaging pipes or other equipment resting on the bottom.

At least 50,000 kilometers (31,000 miles) of pipelines reportedly snake across the seafloor of the Gulf of Mexico. Damage to these pipelines can be difficult to detect if it causes only smaller leaks, rather than a catastrophic break, the researchers say. Repairing underwater pipes can cost more than fixing the offshore oil drilling platforms themselves, making it all the more important to prevent damage to pipelines in the first place.
The researchers, at the U.S. Naval Research Laboratory at Stennis Space Center, Mississippi, got an unprecedented view of a hurricane when Hurricane Ivan, a category-4 storm, crossed the Gulf of Mexico in 2004. The eye of the storm passed over a network of sensors on the ocean floor, put in place to monitor currents along the continental shelf in the Gulf.

The research team found that strong currents along the sea floor pushed and pulled on the seabed, scouring its surface. "Usually you only see this in very shallow water, where waves break on the beach, stirring up sand," says David Wang, co-author of the study. "In hurricanes, the much bigger waves can stir up the seafloor all the way down to 90 meters [300 feet]."

Ivan's waves on the surface created powerful currents that dug up the seafloor. Acoustic measurements using sound waves showed that these currents lofted a lot of sediments, which clouded the water up to 25 meters (82 feet) above the seafloor. The team's seafloor sensors tracking the pressure underwater experienced a big increase, as well. This showed that the ground was washed away beneath the sensors, causing them to sink into a lower, higher-pressure zone.

Using a computer model of wave-induced current stresses, the team estimated how powerful currents would need to be for forces they exert at the sea floor to exceed a "critical force" that triggers sediment suspensions and could lead to underwater mudslides.

According to these estimates, hurricanes considerably weaker than Ivan, which was category-4, could still tear up the seafloor, causing significant damage as deep as 90 meters.

The researchers were surprised by how long the destructive currents persisted after Hurricane Ivan passed by. "The stress on the sea floor lasted nearly a week," says Hemantha Wijesekera, lead author of the study. "It doesn't go away, even after the hurricane passes."

The researchers say they're not sure what strengths of forces underwater oil pipelines are built to withstand. However, "hurricane stress is quite large, so the oil industry better pay attention,"

Wijesekera says.

The Office of Naval Research funded this study.

Maria-Jose Vinas | American Geophysical Union
Further information:
http://www.agu.org

More articles from Studies and Analyses:

nachricht Amputees can learn to control a robotic arm with their minds
28.11.2017 | University of Chicago Medical Center

nachricht The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>